大学英语听力教程第三册（第二版） 听力原文大学英语听力教程第三册（第二版） 听力原文UNIT1Part1 B The Amazon forests are disappearing because of increased burning and tree removal. In September, satellite pictures showed more than 20000 fires burning in the Amazon. Experts say most of these fires were set by farmers. The farmers were attempting to clear land to grow crops. The World Wildlife Fund says another serious problem is that too many trees in the Amazon rain forest are being cut down. The World Wildlife Fund says the fires show the need for urgent international action to protect the worlds rain forests. The group warns that without such action some forests could be lost forever. 2. Environmental issues swell to the full in Berlin this week, for the UN spongsored conference on global warming and climate change is the first such meeting since the Rio summit three years ago. With scientists and governments now generally ready to accept that the earth climate is being affected by emissions of CO2 and other greenhouse gases, over a hundred countries are sending delegations. But how much progress has been made implementing the greenhouse gas reduction target agreed on at Rio? Simon Dary reports.Part2 The earth at risk I: Brian Cowles is the producer of a new series of documentaries called The Earth at Risk which can be seen on Channel 4 later this month. Each program deals with a different continent, doesnt it, Brian? B: Thats right. We went to America, both North and South and then we went over to Africa and South-East Asia. I: And what did you find in each of these continents? B: Starting with Africa, our film shows the impact of the population on the environment. Generally speaking, this has caused the Sahara Desert to expand. Its a bit of a vicious circle we find. People cut down trees for firewood and their domestic animals eat all the available plants and so consequently they have to move south as the Sahara Desert expands further south. I mean, soon the whole of Mali will become a desert. And in East Africa: here the grasslands are supporting too many animals and the result is, of course, theres no grass nothing for the animals to eat. I: I see. And the next film deals with North America? B: Thats right. In the USA, as you know, intensive agriculture requires a plentiful supply of rain for these crops to grow, I mean if there isnt enough rain the crops dont grow. And growing crops stabilize soil, without them the top soil just blows away. This is also true for any region that is intensely farmed most of Europe, for example. I: And what did you find in South America? B: In South America (as in Central Africa and Southern Asia) tropical forests are being cut down at an alarming rate. This is done so that people can support themselves by growing food or to create ranches where cattle can be raised to be exported to Europe or America as tinned meat. The problem is that the soil is so poor that only a couple of harvests are possible before this very thin soil becomes exhausted. And it cant be fed with fertilizers like agricultural land in Europe.For example, in Brazil in 1982 an area of jungle the size of Britain and France combined was destroyed to make way for an iron ore mine. Huge numbers of trees are being cut down for exports as hardwood to Japan, Europe, USA to make things like luxury furniture. These forests cant be replaced the forest soil is thin and unproductive and in just a few years, a jungle has become a waste land. Tropical forests contain rare plants (which we can use for medicines, for example) and animals one animal or plant species becomes extinct every half hour. These forest trees also have worldwide effects. You know, they convert carbon dioxide into oxygen. The consequence of destroying forests is not only that the climate of that region changes (because there is less rainfall) but this change affects the whole world. I mean, over half the worlds rain forest has been cut down this century. Part3sectionA I-Interviewer B-Brian Cowles I: So, Brian, would you agree that what we generally think of as natural disasters are in fact man-made? B: Yes, by and large. I mean, obviously not hurricanes or earthquakes, but take flooding, for example. Practically every year, the whole of Bangladesh is flooded and this is getting worse. You know, the cause is that forests have been cut down up in Nepal and India, I mean higher up-river in the Himalayas. Trees would hold rainfall in their roots, but if theyve been cut down all the rain that falls in the monsoon season flows sraight into the river Ganges and floods the whole country. The reason for flooding in Sudan is the same the forests higher up the Blue Nile in Ethiopia have been destroyed too. I: Well, this all sounds terribly depressing. Um . What is to be done? I m